name = ['pig','dog','cat','bird','elephant']
name[0] = 'tiger'
name.append('lion')
name.remove('bird')
print(len(name))
if 'pig' in name:
    print('1')
else:
    print('You little piggy')    
print (name[0] , name[3])
nam1 = {'jump','christmas','tree','snow','gold'}
nam1.add('Father Christmas')
print(nam1)
nam2 = {2,3,4,5,56,6,7,7}
nam3 = {4,5,5,5,6,4,3,3,4,50}
nam4 = nam2.union(nam3)
nam5 = nam2.difference(nam3)
print(nam4,nam5)
